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Biomedical subjects

S Sandström

Publications and source records attributed to S Sandström.

At least 19 recordsLinked to original sources

[Acute, atraumatic changes of the lower respiratory tract in the child in thoracic roentgen imaging. Recognition and appreciation of radiological changes].

The diagnosis of acute, non-traumatic diseases of the lower respiratory tract requires exact knowledge of the specific anatomy, physiology and pathology of the pediatric chest. The absolutely and relatively smaller airways, as compared with those of adults, and the undeveloped collateral ventilation result in radiological appearances that are unique in children. Viral pneumonia is predominant only in small children up to an age of 2 years. With increasing age, there is a higher incidence of bacterial pneumonia. The differentiation of viral and bacterial etiology of a pneumonia is not possible on the basis of chest radiographs. In acute pediatric imaging, possible aspiration of foreign bodies has to be considered. Since most foreign bodies cannot be detected radiographically, indirect features such as hyperinflation or mediastinal shifts have to be evaluated. Primary lung tumors are rare in children. More common are metastases with known primary tumors. Neuroblastoma or lymphomas may mimic intrapulmonary pathologies.

Adolescent↗

Embolization of hepatic hemangiomas in infants.

A small number of cavernous liver hemangiomas in infants cause serious symptoms, requiring active treatment. We report two newborns with giant liver hemangiomas, treated by intra-arterial embolization. The babies presented at 2 - 8 days after birth with tachypnoea and cardiac dilation. A giant liver hemangioma located in the right liver lobe in one infant and in the left liver lobe in the other was found at ultrasonography and computed tomography. Dilated liver veins indicated abnormal shunting of the blood through the hemangiomas. Because of progress of symptoms superselective embolization of the arteries feeding the hemangiomas and arising from the celiac trunk was performed with a mixture of Lipoidol and Histoacryl. A decrease of tachypnoea and of heart volume was noted after embolization. In one infant surgery was necessary due to gastrointestinal bleeding. The intra-arterial embolization is a valuable method for the treatment of newborns with symptomatic cavernous liver hemangiomas.

Diseases in Twins↗

CP43', the isiA gene product, functions as an excitation energy dissipator in the cyanobacterium Synechococcus sp. PCC 7942.

Under conditions of iron deficiency certain cyanobacteria induce a chlorophyll (Chl)-binding protein, CP43', which is encoded by the isiA gene. We have previously suggested that CP43' functions as a nonradiative dissipator of light energy. To further substantiate its functional role an isiA overexpression construct was introduced into the genome of a cyanobacterium Synechococcus sp. PCC 7942 (giving isiAoe cells). The presence of functional CP43' in isiAoe cells was confirmed by Western blot as well as by the presence of a characteristic blueshift of the red Chl a absorption peak and a notable increase in the 77 K fluorescence peak at 685 nm. Compared to wild-type cells isiAoe cells, with induced CP43', had both smaller functional antenna size and decreased yields of room temperature Chl fluorescence at various light irradiances. These observations strongly suggest that isiAoe cells, with induced CP43', have an increased capacity for dissipating light energy as heat. In agreement with this hypothesis isiAoe cells were also more resistant to photoinhibition of photosynthesis than wild-type cells. Based on these results we have further strengthened the hypothesis that CP43' functions as a nonradiative dissipator of light energy, thus protecting photosystem II from excessive excitation under iron-deficient conditions.

Bacterial Proteins↗

Percutaneous nephrostomy in infants and children.

RATIONALE AND OBJECTIVES: The purpose of this study was to review the authors' experience with percutaneous nephrostomy during an 11-year period, paying special attention to indications and outcomes. MATERIAL AND METHODS: The records of 71 percutaneous nephrostomy procedures performed on 59 children at the authors' institution from January 1987 through December 1997 were retrospectively reviewed. In these children, ultrasonography was used for puncture and fluoroscopy for catheter insertion. Local anesthesia with sedation was used and later replaced by general anesthesia. Loop-end catheters were employed. The smallest patient weighed 1,200 g, and the mean patient age was 3.4 years. RESULTS: The mean duration of drainage was 60 days, and the longest time was 11 months. Indications were mainly obstructions, with congenital obstruction (n = 28) and postoperative obstruction (n = 26) being the most common. Obstructive pyelitis, malignancy, stone, renal cystic disease, trauma, and neurogenic bladder disturbance were also indications. No complications such as loss of the kidney, serious infection, or hemorrhage of clinical importance were observed. Obstruction was successfully relieved in all patients, but 12 kidneys and five hemikidneys did not recover function and were eventually removed. CONCLUSION: The percutaneous nephrostomy procedure is a safe technique that can be used successfully for short- and longterm drainage in all children, even in small infants and those with solitary kidneys, and is a valuable adjunct to surgery.

Child↗

Transcatheter closure of post-infarction ventricular septal defect with the Amplatzer Septal Occluder device.

There is an 80-90% mortality rate within the first 2 months of the occurrence of a post-infarction ventricular septal defect (VSD) with medical treatment alone. The muscular VSD presents a technical problem for the surgeon. Surgical treatment was unsuccessful in two patients. They were treated successfully using the Amplatzer Septal Occluder, with improvement in their condition.

Aged↗

Expression of the isiA gene is essential for the survival of the cyanobacterium Synechococcus sp. PCC 7942 by protecting photosystem II from excess light under iron limitation.

Iron deficiency is known to suppress primary productivity in both marine and freshwater ecosystems. In response to iron deficiency, certain cyanobacteria induce a chlorophyll (Chl)-protein complex, CP43', which is encoded by the isiA gene. The deduced amino-acid sequence of CP43' predicts some structural similarity to the CP43 polypeptide of photosystem II, but the function of CP43' remains uncertain. In order to assess its physiological role, the isiA gene of a cyanobacterium, Synechococcus sp. PCC7942, was inactivated by insertion mutagenesis (giving isiA cells). Compared with isiA cells, under iron deprivation, wild-type cells showed both lower rates of photosystem II-mediated O2 evolution at limiting light irradiances and decreased yields of room temperature Chl fluorescence at various irradiances. These observations strongly suggest that the decreased photosystem II activity in wild-type cells with CP43' is attributable to increased non-radiative dissipation of light energy. In agreement with this hypothesis, isiA cells were more susceptible to photoinhibition of photosynthesis than wild-type cells, resulting in much slower growth rates under iron limitation. Based on these results, we suggest that CP43' functions as a non-radiative dissipator of light energy, thus protecting photosystem II from excessive excitation under iron-deficient conditions.

Bacterial Proteins↗

Successful thrombolysis of an occluded modified Blalock shunt three days after operation.

A 10-day-old boy with pulmonary atresia received a right-sided aortopulmonary polytetrafluoroethylene shunt. Three days after the operation he became cyanotic and was reintubated. Shunt occlusion was confirmed with angiography. Recombinant tissue plasminogen activator was given locally into the proximal end of the shunt. The thrombus was completely resolved after 2 days. When administration of recombinant tissue plasminogen activator was stopped, heparin infusion was started for 5 days. Shunt patency was demonstrated by angiography at 3 months postoperatively.

Anastomosis, Surgical↗

Complex congenital heart malformation evaluated with MR imaging at 0.3 T.

The aim of this study was to evaluate the efficiency of MR imaging at 0.3 T as the single modality in diagnosing complex congenital heart disease (CHD). Films from 45 cases were reviewed in two stages by four specialists and one fellow in pediatric radiology, who were unfamiliar with the patients. First a general review of CHD diagnosis was made, then a detailed study of anomalous venous return was performed. Regarding the general diagnosis of cardiovascular anomalies the results were good, with sensitivity of 80%, specificity of 96%, a positive predictive value of 88%, a negative predictive value of 93% and accuracy of 92%. As expected, the less experienced reviewer had somewhat lower figures. As for detailed evaluation of the anomalous veins, the diagnostic results were again good (sensitivity 85%), although less so when also the connection sites of the anomalous veins were considered (sensitivity 79%). The specificity of the findings was high at 97%. MR imaging at 0.3 T is valuable in the diagnosis of complex CHD, especially for anomalous vessels and their connections.

Child, Preschool↗

Spatial resolution requirements in digital radiography of scaphoid fractures. An ROC analysis.

PURPOSE: To investigate the spatial resolution requirements in digital radiography of scaphoid fractures. MATERIAL AND METHODS: Included in the study were 60 scaphoid radiographs with and 60 without fractures of the scaphoid bone. The film-screen images were digitized using pixel sizes of 115, 170, and 340 microns along with 170 microns with a 10:1 wavelet compression. The digital images were displayed on a 1280 x 1024 x 8 bits monitor, and 5 observers evaluated the images in 5 randomized sessions. The results for each pixel size were then compared to the film-screen images by ROC analysis. RESULTS: The mean area under the ROC curves was larger for the film-screen images than for the digital images at all resolutions. However, this difference was not significant when the areas under the ROC curves for the film-screen images were compared to the digital images of 115, 170, and 170 microns with 10:1 compression. There was a significant difference for the 340-microns pixel size in favour of the film-screen images. The mean ROC curves for the digital images were very similar for the 115 and 170 microns pixel sizes, although slightly better for 115 microns. At 170 microns, the compression seemed to have a relatively small negative effect on the diagnostic performance; the deterioration was greater when the pixel size was increased to 340 microns. There was no obvious correlation between diagnostic performance and the experience of the observers in using work-stations. CONCLUSIONS: The pixel size of 170 microns is adequate for the detection of subtle fractures, even after wavelet compression by a ratio of 10:1.

Angiography, Digital Subtraction↗

Percutaneous translumbar central venous catheter in infants and small children.

Vascular occlusion is a common clinical problem in children dependent on prolonged vascular access. As an alternative to conventional central venous catheter placement we report our experience of four children receiving translumbar inferior vena cava catheter on 12 different occasions. All catheter placements were successful. No procedure-related complications occurred. The median catheter patency was 4.8 months (range 1-10 months). The translumbar route for central venous access is safe and reliable and should be considered when prolonged use is anticipated in infants and small children.

Catheterization, Central Venous↗

Medical health and emotional effects of art stimulation in old age. A controlled intervention study concerning the effects of visual stimulation provided in the form of pictures.

The present article reports on a controlled intervention study of the effects of a nondirected use of pictures as a possible modality for improving well-being in elderly women. Works of art were chosen for the individual taste pattern on the basis of psychological and art scientific research on aesthetic reactions to and perception of art. Participants were randomly allocated either to the intervention (n = 20) or to the control (n = 20) group. Participants in both groups had the same amount of social contact with and attention from the experimenter. The difference between the groups indicated improved well-being in the intervention group, an improvement not seen in the control group. The quantitative analyses of the results reveal a significant improvement of the positive mood parameters happiness, peacefulness, satisfaction and calmness and the negative parameters low-spirited, unhappy and sad. Systolic blood pressure decreased and an improvement was seen in the subjects' medical health status with regard to reported dizziness, fatigue, pain and use of laxatives.

Activities of Daily Living↗

Psychophysiological effects of stimulation with pictures of works of art in old age.

The present article reports on a controlled intervention study concerning the effects of non-directed use of pictures of works of art as a way of stimulating institutionalized elderly women. After the stimulation period differences in ratings between the groups indicated improved well-being in the intervention group. Such improvement was not seen in the C-group. The quantitative analyses of the results reveal a significant change of the parameters happiness, peacefulness, creativeness, social activities and systolic blood pressure. The qualitative analysis shows that the conversations about pictures of works of art in the intervention group give the person free rein to her own imagination and are merely characterized by happiness. In the control group the conversations are to a great extent characterized by downheartedness, despair and complaining.

Aged↗

Ductus arteriosus aneurysm imaging using modern diagnostic methods.

An aneurysm of the ductus arteriosus carries a high risk of rupture. The radiologic findings are described, based on a review of the literature, and on our experience of 5 patients, successfully diagnosed and treated. A left-sided mediastinal mass is always present, obscured only if the aneurysm has already ruptured. Although the lesion seems to be congenital, conventional radiology sometimes demonstrates wall calcifications. Ultrasonography is well suited to demonstrate the vascular nature of the mass, but interpretation may be difficult because of intervening air-containing lung parenchyma. CT, especially using dynamic scanning with contrast enhancement, is an excellent noninvasive diagnostic method. Angiography is frequently necessary to demonstrate patency or occlusion of the aortic and pulmonary ends of the ductus. The differential diagnosis must include a large number of mediastinal tumors. A temporary widening of the ductus in the newborn is common and must be differentiated from a true aneurysm. Surgical treatment today is usually successful.

Aneurysm↗

Articulotrochanteric distance in slipped capital femoral epiphysis.

The difference in altitude between the proximal limit of the femoral head and the tip of the greater trochanter--the articulotrochanteric distance (ATD)--was recorded in 312 patients with slipped capital femoral epiphysis and compared with that in normal hips. The ATD was markedly reduced after severe slipping, independent of the method of treatment. In mild or moderate slippings, the ATD differed with the method of treatment. The shortest ATD was seen after osteosynthesis with AO screws. Nonoperative treatment and osteosynthesis with the Johansson nail or Nyström pin caused a slight reduction of the ATD, while no reduction was seen after hook-pinning. These differences probably reflect various degrees of damage to the subcapital growth plate, which may result in leg length difference and abduction insufficiency.

Adolescent↗

Bilaterality in slipped upper femoral epiphysis.

The frequency of slipping and osteoarthritis of the contralateral hip was recorded in 260 patients with slipped upper femoral epiphysis between 1910 and 1960. Twenty-three of these patients (9%) had primary bilateral slipping, 32 (12%) had a contralateral slip diagnosed later during adolescence and a further 104 (40%) had signs of contralateral slipping at follow-up 16 to 66 years later, giving a total of 159 cases (61%) with bilateral slips. Of the 104 slippings diagnosed at follow-up, 25% showed osteoarthritis. It is concluded that, with a slipped epiphysis, prophylactic contralateral pinning should be performed to avoid slipping and to reduce the risk of osteoarthritis.

Adolescent↗

The calcar femorale as a landmark in hip physiolysis.

The position of the femoral head in relation to the calcar femorale was analyzed from 120 radiographs of normal hips. A constant relationship was found, providing a method of calculating the normal position of the femoral head. The method was tested in 56 cases with physiolysis of the hip and was found to be useful in determining the degree of slipping in both adolescents and adults.

Adolescent↗

Long-term effects of physical exercise on working capacity and pulmonary function in cystic fibrosis.

Seven patients with cystic fibrosis aged 6 to 20 were enrolled for 30 months in a daily exercise program. After 12 months conventional chest physiotherapy was withdrawn. Patients with low initial Shwachman scores improved as regards maximal working capacity. Spirometric data and volume of trapped gas indicated opening of closed airways. We suggest that physical exercise in general should be the basis of pulmonary therapy in cystic fibrosis. Other forms of physiotherapy are advisable when hard physical exercise is not feasible.

Adolescent↗